200821670 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種液晶顯示裝置，特別係關於一種可 控制視角範圍之液晶顯示裝置。 【先前技術】 液晶顯示裝置具有無輻射、輕薄及省電等優點，已廣 泛應用於各種資訊、通訊、消費性產品中。一般液晶顯示 裝置根據不同需要朝兩方面發展：在個人使用方面，盡可 能使視角最小化，防止文件信息泄漏；在商務使用和家庭 使用方面’盡可能使視角最大化，以便更多人共享使用。 目前，顯示器均做成超廣視角類型，再以防窺膜實現較小 視角特性。 請參閱圖1，係一種先前技術液晶顯示裝置之暗態工 作示意圖。該液晶顯示裝置100包括一液晶顯示面板1〇 及一與其相鄰設置之背光模組20。該液晶顯示面板1Q包 ，括一第一玻璃基板11、一與該第一玻璃基板11平行相對 設置之第二玻璃基板12、一液晶層13、一上偏光板14、 一下偏光板15、複數條形正電極121、複數條形負電極122 及二配向膜（圖未示）。該液晶層13夾於該第一玻璃基板U 與該第二玻璃基板12之間。該條形正電極121與該條形負 電極122相對平行設置於該第二玻璃基板12之鄰近液晶層 13 —側。該下偏光板15設置於該第二玻璃基板I]之遠離 液晶層13 —侧。該上偏光板14設置於該第一玻璃基板u 之遠離液晶層13 —側。該二配向膜分別設置於該第一玻璃 6 200821670 基板11與該第二玻璃基板12之鄰近液晶層13 一側。該下 ‘偏光板15之偏振方向κ與該條形正電極121及該條形負 •電極I22成45。夾角。該二配向膜之配向方向與下偏光板 15之偏振方向κ 一致。 -田該條形正電極121與該條形負電極122未被加電壓 牯，該液aa分子18之長軸均沿配向膜之配向方向排列，即 該液晶分子18亦沿下偏光板15之偏振方向K排列。而上 :偏光板14之偏振方向L與下偏光板15之偏振方向κ相互 垂直。由背光模組20發出之光束經過下偏光片15後變為 κ方向之偏振光，該偏振光經過液晶層13後，偏振方向依 然是K，與上偏振片14之偏振方向[相互垂直，因此光 束不能通過，該液晶顯示面板1〇顯示暗態。 —請參閱圖2，係圖i所示液晶顯示裝置⑽之亮態工 作示意圖。當該條形正電極121與該條形負電極122被施 加電麼時，該二電極121、122之間產生—電場’該電場使 、液晶分子18在平行於第—玻璃基板^與第二玻璃基板^ 之平面内發生扭轉，從而使經過下偏光片15後之κ方向 之偏振光經過液晶層13後偏振方向發生改變，其中與上偏 振片14之偏振方向L -致之光分量通過。通過調節電麼 來控制液晶分子18之旋轉角度，以調制光束之通過率，進 而可實現晝面顯示。在顯示過程中，觀察者任何時候都口 看到液晶分子18之短軸，因此在各個角度上所觀看到之畫、 面都不會有大差別，進而可擴大該液晶顯示面板H)之^ 角0 7 200821670 當需要改變視角範圍時，需要在该液晶顯示面板1〇 _外部貼附一張防窺膜，該防窺膜採用微型百葉技術，同百 •葉窗類似，只能在一定角度範圍内看到屏幕内容。該防窺 膜在水平方向把視角範圍限制在6〇度以内。如果從左、右 視角超過30度之方向觀看屏幕，只能看到漆黑晝面。 雖然貼附防窺膜可以控制視角範圍在一個較合理之區 域，但液晶顯示裝置100由廣視角切換到窄視角之操作不 ,方便，且如果防窺膜貼附不平整，則影響正常使金 面質量。 、旦 【發明内容】 有鑑於此，提供一種視角切換較簡單之液晶顯示裝置 實為必需。 一種液晶顯示裝置，其包括一液晶顯示面板，一高分 子分散液晶膜及一背光模組。該液晶顯示面板與該背光模 組相對設置。該高分子分散液晶膜夾於該液晶顯示面板與 i該背光模組之間。該高分子分散液晶膜未被施加電壓時使 該背光模組發出之光束發散，該高分子分散液晶膜被施加 電壓時使該背光模組發出之垂直於該高分子分散液晶膜之 光束直接穿透。 ' 相較於先前技術，本發明液晶顯示裝置可藉由是否對 該高分子分散液晶膜施加電壓而進行視角切換，操作簡單 方便。 【實施方式】 請參閱圖3,係本發明液晶顯示裝置一較佳實施方式 8 200821670 之侧視圖。該液晶顯示裝置300包括一廣視角液晶顯示面 板1、一高分子分散液晶膜2(Polymer Dispersed Liquid Crystal Film, PDLC)及一背光模組3。該廣視角液晶顯示面 板1與該背光模組3平行相對設置。該高分子分散液晶膜 2夾於該廣視角液晶顯示面板1與該背光模組3之間，且 平行於該廣視角液晶顯示面板1與該背光模組3。該背光 模組3包括一稜鏡片31及一導光板32。該稜鏡片31設置 於該導光板32與該高分子分散液晶膜2之間。 該導光板32包括一出光面321，該出光面321定義複 數連續之V形凹槽，該V形凹槽將出射光束向垂直於稜鏡 片31之方向匯聚。該稜鏡片31進一步將出射光束向垂直 於該高分子分散液晶膜2之方向匯聚。故，由背光模組3 發出之光束絕大多數垂直於該高分子分散液晶膜2。 請參閱圖4，係圖3所示液晶顯示裝置之高分子分散 液晶膜2之結構示意圖。該高分子分散液晶膜2包括一第 一透明電極層23、一第二透明電極層24、複數液晶微滴 25及高分子聚合物26。該液晶微滴25與該高分子聚合物 26夾於該第一透明電極層23與該第二透明電極層24之 間。該複數液晶微滴25均勻地分佈於該高分子聚合物26 中0 該液晶微滴25之大小在1 // m與4 // m之間。光束沿 著液晶分子28長轴方向傳播時，光波電場振動方向皆垂直 於该液晶分子28長軸，光速皆相同，稱為尋常光，定義其 折射率為尋常光折射率。該液晶分子28之尋常光折射率在 9 200821670 1.4與1·5之間。該高分子聚合物26之折射率在1.4與1·5 之間。該高分子聚合物26可為聚乙烯醇（Polyvinyl Alcohol, PVA)、三醋酸纖維素（Triacetyl Cellulose Film，TAC)或者聚 甲基丙烯酸曱酯（Polymethyl Methacrylate, PMMA)，其折 射率分別為1.446、1.485及1.49。 請一併參閱圖5與圖6，圖5係圖4所示高分子分散 液晶膜2未被施加電壓時之光路原理示意圖。該背光模組 3發出之光束中，定義垂直於該高分子分散液晶膜2之光 束為a光束，非垂直於高分子分散液晶膜2之光束為b光 束。 該第一透明電極層23與該第二透明電極層24未被施 加電壓時，該液晶微滴25中液晶分子28呈雙極排列，並 且軸向各異。該液晶微滴25在各個方向上之折射率不同於 該液晶分子28之尋常光折射率，而该高分子聚合物26之 折射率與該液晶分子28之尋常光折射率基本相同，故，二 者在各個方向上之折射率不相同。故，a光束與b光束入 射後均在該液晶微滴25與高分子聚合物26之界面發生散 射，使從該高分子分散液晶膜2出射之光束發散，從而使 該液晶顯示裝置300實現廣視角。其中，該廣視角液晶顯 示面板1係採用平面内切換（In_Plane Switching，IPS)技術 之液晶顯不面板’該廣視角液晶顯不面板1使該液晶顯不 裝置300之廣視角效果更佳。 圖6係圖4所示高分子分散液晶膜2被施加電壓時之 光路原理示意圖。當對該第一透明電極層23與該第二透明 200821670 電極層24施加電屋時，產生 23與該第二透明電極層尸直：：第-透明電極層 25中液晶分子28之具細電麥’該電場使該液晶微滴 之入射方向上，液曰微=場方向平行排列。在a光束 常光折射率相同因;^古^^率料晶分子Μ之尋 微滴25之折射t ^ 子聚合物％之折射率與液晶 微满25之折射率基本相同。故 25界面不發生散射，直接穿透。 射後在液晶微滴 於曰广射ί向上’该液晶微滴25之折射率不同 2=:lt 常光折射率，因此該高分子聚合物 :6之折射率與液晶微滴25之折射率不相同。故，&光束入 射後在液晶微滴25界面g 4 u > A^，^旦、面發生折射。該b光第一次折射後變 ς 里》解為—垂直分量ci與-水平分量c2， 同，光束一樣，直接穿透該高分子分散液 曰曰膜2。該水Β ! e2遇到液晶微滴25界 射舌；折射後之光束定義為d光束，該d光束矢量分解為 1直分：dl與一水平分量d2。其中，該垂直分量以直 接穿透該高分子分散液晶臈2’該水平分量d2經過下一個 液晶微滴25時再次發生折射，折射過程與光束e2相同。 經過多次折射後’該斜向入射光b之斜向出射量很少，從 該高分子分散液晶膜2出射之光束基本垂直於該廣視角液 晶顯示面1。由於斜向出射量很少，故斜向亮度不足而 不可視，從而使該液晶顯示裝置3〇〇實現窄視角。 由^於該液晶顯示裝£ 3〇〇⑽一高分子分散液晶膜 2’該高分子分散液晶膜2未被施加電壓時，使從該高分子 11 200821670 分散液晶膜2出射之光束發散，從而使該液晶顯示裝置獅 實現廣視A It兩分子分散液晶膜2被施加電I時，使從 ，高分子分散液晶膜2出射之光束基本垂直於該廣視角液 曰曰’”、員7F面板1 ’攸而使該液晶顯示裝置細實現窄視角。 該液晶顯示裝置_可藉^否對該高分子分散液晶膜2 施加電壓而進行視角切換，操作簡單方便。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of controlling a viewing angle range. [Prior Art] The liquid crystal display device has the advantages of no radiation, lightness, and power saving, and has been widely used in various information, communication, and consumer products. Generally, liquid crystal display devices are developed in two aspects according to different needs: in terms of personal use, the viewing angle is minimized as much as possible to prevent leakage of file information; in terms of business use and home use, the viewing angle is maximized so that more people can share it. . At present, the displays are made into an ultra-wide viewing angle type, and the anti-spy film is used to achieve a smaller viewing angle characteristic. Please refer to FIG. 1, which is a schematic diagram of a dark state operation of a prior art liquid crystal display device. The liquid crystal display device 100 includes a liquid crystal display panel 1A and a backlight module 20 disposed adjacent thereto. The liquid crystal display panel 1Q includes a first glass substrate 11, a second glass substrate 12 disposed in parallel with the first glass substrate 11, a liquid crystal layer 13, an upper polarizing plate 14, a lower polarizing plate 15, and a plurality of A strip-shaped positive electrode 121, a plurality of strip-shaped negative electrodes 122 and two alignment films (not shown). The liquid crystal layer 13 is sandwiched between the first glass substrate U and the second glass substrate 12. The strip-shaped positive electrode 121 is disposed in parallel with the strip-shaped negative electrode 122 on the side adjacent to the liquid crystal layer 13 of the second glass substrate 12. The lower polarizing plate 15 is disposed on the side of the second glass substrate I] away from the liquid crystal layer 13. The upper polarizing plate 14 is disposed on a side of the first glass substrate u away from the liquid crystal layer 13. The two alignment films are respectively disposed on the side of the first glass 6 200821670 substrate 11 and the second glass substrate 12 adjacent to the liquid crystal layer 13 . The lower polarization direction κ of the polarizing plate 15 is 45 with the strip-shaped positive electrode 121 and the strip-shaped negative electrode I22. Angle. The alignment direction of the two alignment films coincides with the polarization direction κ of the lower polarizing plate 15. - The strip-shaped positive electrode 121 and the strip-shaped negative electrode 122 are not applied with a voltage, and the long axes of the liquid aa molecules 18 are arranged along the alignment direction of the alignment film, that is, the liquid crystal molecules 18 are also along the lower polarizing plate 15 The polarization directions K are arranged. Further, the polarization direction L of the polarizing plate 14 and the polarization direction κ of the lower polarizing plate 15 are perpendicular to each other. The light beam emitted by the backlight module 20 passes through the lower polarizer 15 and becomes polarized light in the κ direction. After the polarized light passes through the liquid crystal layer 13, the polarization direction is still K, and the polarization direction of the upper polarizing plate 14 is perpendicular to each other. The light beam cannot pass, and the liquid crystal display panel 1 〇 displays a dark state. - Please refer to Figure 2, which is a schematic diagram of the bright state of the liquid crystal display device (10) shown in Figure i. When the strip-shaped positive electrode 121 and the strip-shaped negative electrode 122 are applied with electricity, an electric field is generated between the two electrodes 121 and 122, and the liquid crystal molecules 18 are parallel to the first glass substrate and the second The surface of the glass substrate is twisted so that the polarization direction of the κ direction after passing through the lower polarizer 15 passes through the liquid crystal layer 13, and the polarization direction changes, and the light component of the polarization direction L of the upper polarizing plate 14 passes. The rotation angle of the liquid crystal molecules 18 is controlled by adjusting the electric power to modulate the passing rate of the light beam, thereby achieving the kneading surface display. During the display process, the observer sees the short axis of the liquid crystal molecules 18 at any time, so that the picture and the surface viewed at various angles are not greatly different, and the liquid crystal display panel H) can be enlarged. Angle 0 7 200821670 When it is necessary to change the range of viewing angle, it is necessary to attach a peeping film to the outside of the liquid crystal display panel. The peeping film adopts micro louver technology, similar to the louver window, and can only be at a certain angle. See the screen content within the scope. The privacy film limits the viewing angle range to 6 degrees in the horizontal direction. If you look at the screen from the left and right angles of more than 30 degrees, you can only see the black face. Although attaching the anti-spy film can control the viewing angle range in a reasonable area, the operation of switching the liquid crystal display device 100 from the wide viewing angle to the narrow viewing angle is not convenient, and if the anti-spy film is attached unevenly, the effect is normal. Surface quality. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a liquid crystal display device with a simple viewing angle switching. A liquid crystal display device comprising a liquid crystal display panel, a high molecular dispersion liquid crystal film and a backlight module. The liquid crystal display panel is disposed opposite to the backlight module. The polymer dispersed liquid crystal film is sandwiched between the liquid crystal display panel and the backlight module. When the polymer dispersed liquid crystal film is not applied with a voltage, the light beam emitted by the backlight module is diverged, and when the voltage of the polymer dispersed liquid crystal film is applied, the light beam emitted from the backlight module perpendicular to the polymer dispersed liquid crystal film is directly worn. through. Compared with the prior art, the liquid crystal display device of the present invention can perform viewing angle switching by applying a voltage to the polymer dispersed liquid crystal film, and the operation is simple and convenient. Embodiments Please refer to FIG. 3, which is a side view of a preferred embodiment 8 200821670 of a liquid crystal display device of the present invention. The liquid crystal display device 300 includes a wide viewing angle liquid crystal display panel 1, a polymer dispersed liquid crystal film (PDLC), and a backlight module 3. The wide viewing angle liquid crystal display panel 1 is disposed in parallel with the backlight module 3. The polymer dispersed liquid crystal film 2 is sandwiched between the wide viewing angle liquid crystal display panel 1 and the backlight module 3, and is parallel to the wide viewing angle liquid crystal display panel 1 and the backlight module 3. The backlight module 3 includes a cymbal 31 and a light guide 32. The cymbal sheet 31 is disposed between the light guide plate 32 and the polymer dispersed liquid crystal film 2. The light guide plate 32 includes a light exiting surface 321 defining a plurality of continuous V-shaped grooves that converge the outgoing light beams in a direction perpendicular to the cymbal sheet 31. The cymbal sheet 31 further converges the outgoing light beam in a direction perpendicular to the polymer dispersed liquid crystal film 2. Therefore, most of the light beams emitted from the backlight module 3 are perpendicular to the polymer dispersed liquid crystal film 2. Referring to Fig. 4, there is shown a schematic structural view of a polymer dispersed liquid crystal film 2 of the liquid crystal display device shown in Fig. 3. The polymer dispersed liquid crystal film 2 includes a first transparent electrode layer 23, a second transparent electrode layer 24, a plurality of liquid crystal droplets 25, and a high molecular polymer 26. The liquid crystal droplets 25 and the polymer 26 are sandwiched between the first transparent electrode layer 23 and the second transparent electrode layer 24. The plurality of liquid crystal droplets 25 are uniformly distributed in the polymer 26. The size of the liquid crystal droplets 25 is between 1 // m and 4 // m. When the light beam propagates along the long axis of the liquid crystal molecules 28, the direction of the electric field of the light wave is perpendicular to the long axis of the liquid crystal molecules 28, and the speed of light is the same, which is called ordinary light, and its refractive index is defined as the ordinary light refractive index. The ordinary light refractive index of the liquid crystal molecule 28 is between 9 200821670 1.4 and 1.5. The high molecular weight polymer 26 has a refractive index between 1.4 and 1.5. The polymer 26 may be polyvinyl alcohol (PVA), Triacetyl Cellulose Film (TAC) or polymethyl Methacrylate (PMMA), and its refractive index is 1.446, respectively. 1.485 and 1.49. Referring to Fig. 5 and Fig. 6, Fig. 5 is a schematic view showing the principle of the optical path when the polymer dispersed liquid crystal film 2 shown in Fig. 4 is not applied with a voltage. Among the light beams emitted from the backlight module 3, a light beam perpendicular to the polymer dispersed liquid crystal film 2 is defined as a light beam, and a light beam non-perpendicular to the polymer dispersed liquid crystal film 2 is a b light beam. When the first transparent electrode layer 23 and the second transparent electrode layer 24 are not applied with a voltage, the liquid crystal molecules 28 in the liquid crystal droplets 25 are arranged in a bipolar manner and have different axial directions. The refractive index of the liquid crystal droplets 25 in each direction is different from the ordinary refractive index of the liquid crystal molecules 28, and the refractive index of the high molecular polymer 26 is substantially the same as the ordinary refractive index of the liquid crystal molecules 28, so The refractive index is different in all directions. Therefore, both the a-beam and the b-beam are scattered at the interface between the liquid crystal droplet 25 and the polymer 26, and the light beam emitted from the polymer-dispersed liquid crystal film 2 is diverged, thereby realizing the liquid crystal display device 300. Perspective. The wide viewing angle liquid crystal display panel 1 is a liquid crystal display panel using an In-Plane Switching (IPS) technology. The wide viewing angle liquid crystal display panel 1 makes the wide viewing angle effect of the liquid crystal display device 300 better. Fig. 6 is a schematic view showing the principle of the optical path when a voltage is applied to the polymer-dispersed liquid crystal film 2 shown in Fig. 4. When the electric house is applied to the first transparent electrode layer 23 and the second transparent 200821670 electrode layer 24, 23 and the second transparent electrode layer are generated: the liquid crystal molecules 28 in the first transparent electrode layer 25 are finely charged. The electric field causes the liquid crystal droplets to be incident in the direction in which the liquid helium micro = field direction is arranged in parallel. The refractive index of the a-beam is the same as that of the normal light; the refractive index of the seed crystal is 折射. The refraction of the droplet 25 is the same as the refractive index of the liquid crystal micro-full 25 . Therefore, the interface does not scatter and penetrate directly. After the shot, the refractive index of the liquid crystal droplet 25 is different from the liquid crystal droplets. The refractive index of the liquid crystal droplet 25 is different from that of the liquid crystal droplet 25, so the refractive index of the polymer: 6 and the refractive index of the liquid crystal droplet 25 are not the same. Therefore, after the beam is incident, the surface of the liquid crystal droplet 25 is refracted at the interface g 4 u > The b light is refracted after the first refraction, and the solution is a vertical component ci and a horizontal component c2, and, like the light beam, directly penetrates the polymer dispersion ruthenium film 2. The water Β e2 encounters the liquid crystal droplet 25 boundary tongue; the refracted beam is defined as the d beam, and the d beam vector is decomposed into 1 straight line: dl and a horizontal component d2. Wherein, the vertical component is refracted again when the horizontal component d2 directly penetrates the polymer dispersed liquid crystal 2' passes through the next liquid crystal droplet 25, and the refraction process is the same as that of the light beam e2. After a plurality of refractions, the oblique incident light b has a small amount of oblique emission, and the light beam emitted from the polymer dispersed liquid crystal film 2 is substantially perpendicular to the wide viewing angle liquid crystal display surface 1. Since the amount of oblique emission is small, the oblique luminance is insufficient to be invisible, so that the liquid crystal display device 3 has a narrow viewing angle. When the polymer dispersed display liquid crystal film 2 is not applied with a voltage, the light beam emitted from the polymer 11 200821670 dispersed liquid crystal film 2 is diverged, thereby When the liquid crystal display device lion realizes the wide-view A It two-molecule dispersed liquid crystal film 2, when the electric current I is applied, the light beam emitted from the polymer dispersed liquid crystal film 2 is substantially perpendicular to the wide viewing angle liquid 曰曰 '", the member 7F panel 1 '攸, the liquid crystal display device can realize a narrow viewing angle. The liquid crystal display device can switch the viewing angle by applying a voltage to the polymer dispersed liquid crystal film 2, and the operation is simple and convenient.
另外，該導光板32之出光面321具有複數連續之V 型凹槽’使導光板32㈣光束出射時進—步㈣直於該稜 鏡片31之方向匯聚，從而使該液晶顯示裝置3⑼之窄視角 效果更佳。 本發明液晶顯不裝置3〇〇之導光板32具有變更設計， 如.該導光板32進一步包括一底面，該底面具有内凹之微 ，鏡結構，其進-步使該導光板32之出射光束向垂直於該 咼分子分散液晶臈2之方向匯聚。該液晶分子28之尋常光 折射率不限於L4至^之間，該高分子聚合物26亦不侷 限於上述三種’折射率與液晶分+ 28之尋常光折射率基本 相同之高分子聚合物均可。 綜上所述，本發明確已符合發明之要件，爰依法提出 專利申請。惟，以上所述者僅為本發明之較佳實施方式， 本發明之範圍並不以上述實施方式為限，舉凡熟習本案技 藝之人士援依本發明之精神所作之等效修飾或變化，皆應 涵蓋於以下申請專利範圍内。 μ 【圖式簡單說明】 圖1係一種先前技術液晶顯示裝置之暗態工作示意圖。 12 200821670 圖2係圖1所示液晶顯示裝置之亮態工作示意圖。 圖3係本發明液晶顯示裝置一較佳實施方式之側視圖。 圖4係圖3所示液晶顯示裝置之高分子分散液晶膜結構示 意圖。 圖5係圖4所示高分子分散液晶膜未被施加電壓時之光路 原理不意圖。 圖6係圖4所示高分子分散液晶膜被施加電壓時之光路原 理示意圖。 【主要元件符號說明】 液晶顯示裝置 300 廣視角液晶顯不面板 1 第一透明電極層 23 高分子分散液晶膜 2 第二透明電極層 24 背光模組 3 液晶微滴 25 稜鏡片 31 高分子聚合物 26 導光板 32 液晶分子 28 出光面 321 13In addition, the light-emitting surface 321 of the light guide plate 32 has a plurality of continuous V-shaped grooves ′ to cause the light guide plate 32 (four) to emit light, and the step (4) is concentrated directly in the direction of the cymbal 31, so that the liquid crystal display device 3 (9) has a narrow viewing angle. The effect is better. The light guide plate 32 of the liquid crystal display device of the present invention has a modified design. For example, the light guide plate 32 further includes a bottom surface having a concave surface and a mirror structure for further ejecting the light guide plate 32. The light beam converges in a direction perpendicular to the erbium-dispersing liquid crystal 臈2. The ordinary light refractive index of the liquid crystal molecules 28 is not limited to between L4 and ^, and the high molecular polymer 26 is not limited to the above-mentioned high molecular polymers having the same refractive index as the ordinary light refractive index of the liquid crystal fraction + 28 can. In summary, the present invention has indeed met the requirements of the invention, and has filed a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or changes in accordance with the spirit of the present invention. It should be covered by the following patent application. μ [Simplified description of the drawings] Fig. 1 is a schematic diagram of a dark state operation of a prior art liquid crystal display device. 12 200821670 FIG. 2 is a schematic diagram of a bright state operation of the liquid crystal display device shown in FIG. Figure 3 is a side elevational view of a preferred embodiment of a liquid crystal display device of the present invention. Fig. 4 is a view showing the structure of a polymer dispersed liquid crystal film of the liquid crystal display device shown in Fig. 3. Fig. 5 is a schematic view showing the principle of the optical path when the polymer-dispersed liquid crystal film shown in Fig. 4 is not applied with a voltage. Fig. 6 is a schematic view showing the optical path of the polymer-dispersed liquid crystal film shown in Fig. 4 when a voltage is applied. [Description of main component symbols] Liquid crystal display device 300 Wide viewing angle liquid crystal display panel 1 First transparent electrode layer 23 Polymer dispersed liquid crystal film 2 Second transparent electrode layer 24 Backlight module 3 Liquid crystal droplets 25 Sepals 31 Polymer 26 light guide plate 32 liquid crystal molecules 28 light emitting surface 321 13